A distracted driver may leave a vehicle with an automatic transmission unattended without placing the vehicle in a park position and shutting off the vehicle, which may result in unintended vehicle motion. Some vehicles employ a system that monitors excessive acceleration or driver presence after the engine is started with the gear selector in a non-drive position. If the gear selector is moved into a drive position, the system initiates a timer to deliver a signal for a predetermined period of time. That signal is employed to disable the engine if an acceleration or throttle measuring device indicates that excessive acceleration is occurring, or if a seat sensor device indicates that the driver is not present.
Another system employs the emergency brake and engine kill switch. A microprocessor monitors a weight sensor and velocity sensor and, upon detection of the weight in the driver's seat falling outside a predetermined range and the speed of the vehicle being below a predetermined threshold, the emergency brake actuator and engine kill switch are activated to arrest motion of the vehicle.